The present invention relates to a stabilizer system for two wheeled vehicles, particularly vehicles which are powered by a rider. The invention relates most particularly, but not exclusively, to pedal bicycles and pedal-assisted bicycles.
The rider of a bicycle experiences frequent stops and starts in urban areas due to road intersections, slow moving traffic and traffic congestion, road works and other obstructions. These conditions are a common occurrence for cyclists in towns and in urban areas and can result in potentially dangerous situations where the cyclist has to stop precipitately and may lose his or her balance in the process.
In such traffic conditions, the cyclist has to put one or both feet on the ground at each stop and in many instances may have to dismount partially. The frequent and often abrupt stops and starts in traffic are highly inconvenient to the cyclist. They may also be potentially dangerous through loss of balance, impatient behaviour due to frustration and the like, particularly when the traffic includes heavy trucks.
The design of the pedal bicycle and the physical dimensions of the rider often result in saddle seats which are set either too low for maintaining efficient pedal pressure or too high for remaining in the saddle when at the halt. This can lead to frequent dismounting and remounting.
There is described in WO90/09918 A1 a stabilizer system, particularly for bicycles, which incorporates an arm pivoted at its upper end at or adjacent the rear wheel spindle of the vehicle and having at its lower end a cross shaft carrying stabilizers and a wheel-engaging roller, and means for lowering the arm to draw the cross shaft beneath the wheel, so that the tire on the wheel engages the roller and the wheel is lifted off the ground. With this arrangement a large part of the weight of the rider is transferred to the ground through the wheel, the roller, the cross shaft and the stabilizers.
The means for lowering the arm described in W090/09918 A1 comprises a spool on the pedal spindle, the arm being lowered by back-pedalling to draw a cable from the lower end of the arm onto the spool. While this arrangement is satisfactory, some cyclists do not find back-pedalling as they come to the halt easy to control or achieve. Moreover, power to lower the arm has to be provided by the rider. Also, the arrangement, while capable of being designed to be added to an existing bicycle, is particularly suited to being fitted as original equipment. Accordingly it is an object of the present invention to provide, in a stabilizer system of the general construction described, an alternative means of lowering the arm which can deal with one or more of these points.